Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 78023 — Helotes, TX

ZIP code 78023 (Helotes, Bexar County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is February 18 and the first fall frost December 9.

Where ZIP 78023 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone8b15 to 20 °F

Coldest night−9.4 to −6.7 °C

Last frostFeb 18

First frostDec 9

2012 zone8b

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 8b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Helotes, TX…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Helotes, TX

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostFebruary 18median — 50% chance of a later frost

Safe for tender plantsMarch 16only 10% chance of frost after

First fall frostDecember 9median — 10% chance by Nov 17

Growing season296 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 31 and returns around December 29.

From the NOAA station San Antonio/Seaworld, TX — 12 miles away, elevation 942 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 78023

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Jan 7 – Jan 21

SpinachSow outdoors · Jan 7 – Jan 28

Broccoli, cabbageStart indoors · Dec 10 – Dec 24

Broccoli, cabbageTransplant · Jan 28 – Feb 11

Onion setsPlant outdoors · Jan 21 – Feb 4

PotatoesPlant outdoors · Jan 28 – Feb 11

LettuceSow outdoors · Jan 21 – Feb 4

Carrots, beetsSow outdoors · Jan 28 – Feb 11

TomatoesStart indoors · Dec 24 – Jan 7

TomatoesTransplant · Feb 25 – Mar 11

Peppers, eggplantStart indoors · Dec 10 – Dec 24

Peppers, eggplantTransplant · Mar 4 – Mar 18

BeansSow outdoors · Feb 25 – Mar 11

Sweet cornSow outdoors · Feb 25 – Mar 11

Cucumbers, squashSow outdoors · Feb 25 – Mar 11

Fall lettuce, spinachSow outdoors · Oct 14 – Oct 28

GarlicPlant cloves · Nov 25 – Dec 30

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 18) and first fall frost (Dec 9) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 78023 came on Jan 29 — about the same time as the 1991–2020 average (Jan 29).

average
Jan 292026
Jan 29

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 8b in Texas

620 plants native to the lower 48 states, recorded in Texas, and rated by the USDA to survive 15 °F or colder — the bottom of zone 8b. Each links to its USDA PLANTS profile.

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Helotes, TX.

Soil in Helotes, TX

The soil mapped at the center of ZIP 78023 is Brackett — gravelly clay loam, well drained.

TextureGravelly clay loamholds water and nutrients; slow to drain and warm up

pH7.9alkaline; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2%moderate

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Brackett-Eckrant association, 20 to 60 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 78023; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Helotes, TX

Summer high99 °Faverage high, August

Winter low43 °Faverage low, January

Hot days123days a year at 90 °F or more

Freezing nights14nights a year at 32 °F or less

Growing degree days7,892base 50 °F — the season’s usable heat

Longest day14 h 03 mindaylight on June 21

Shortest day10 h 14 mindaylight on December 21

Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb

Precipitation35.8 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: San Antonio/Seaworld, TX (12 mi away); precipitation: Helotes 2.4 Nnw, TX (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

5 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

782558b

San Antonio, TX · 6 mi

782549a

San Antonio, TX · 7 mi

782569a

San Antonio, TX · 8 mi

782499a

San Antonio, TX · 9 mi

782509a

San Antonio, TX · 10 mi

780638b

Pipe Creek, TX · 10 mi

780158b

Boerne, TX · 10 mi

782539a

San Antonio, TX · 11 mi

Texas planting zones →

Questions about 78023

What planting zone is ZIP code 78023?

ZIP code 78023 (Helotes, TX) is in USDA hardiness zone 8b on the 2023 map: the coldest night of an average winter reaches 15 to 20 °F (−9.4 to −6.7 °C).

When is the last frost in Helotes, TX?

The median last spring frost (32 °F) near 78023 is February 18; after March 16 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, San Antonio/Seaworld station.

When is the first frost in Helotes, TX?

The median first fall frost near 78023 is December 9, giving a median frost-free growing season of 296 days.

When should I plant tomatoes in 78023?

Start tomato seeds indoors around Dec 24 – Jan 7 and set transplants outside around Feb 25 – Mar 11, one to three weeks after the median last frost.

How much rain and snow does 78023 get?

About 35.8 inches of precipitation a year (NOAA 1991–2020 normals, Helotes 2.4 Nnw station).

How hot do summers get in Helotes, TX?

The average high peaks at 99 °F in August, with about 123 days a year at 90 °F or more.

What kind of soil does 78023 have?

The USDA soil survey maps Brackett at the center of ZIP 78023: gravelly clay loam, well drained, pH about 7.9 (alkaline).

Did spring come early in Helotes, TX in 2026?

Spring leaf-out near 78023 came on Jan 29 in 2026, about the same as the 1991–2020 average (Jan 29), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Helotes, TX?

Short-day onions: the longest day near 78023 is 14 h 03 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.